记录一次微信PC授权登录以及微信公众号授权登录开发过程

引进微信PC登录和微信公众号登录功能
1.微信PC登录
需要前往微信开放平台注册一个账号，并创建一个网站应用，成功后这个拿到这个网站应用的appid与secrect

String APPID=(String) weixinLogin.get("appid");
//CommonConstants.contextPath 为项目前缀
String REDIRECT_URI= 
URLEncoder.encode(CommonConstants.contextPath+"/app/weixinAuthLogin");
//pc网页微信登录的scope类型为snsapi_login  微信公众号的scope类型为snsapi_userinfo
String redirectUrl="redirect:https://open.weixin.qq.com/connect/qrconnect?appid="+APPID+"&redirect_uri="+REDIRECT_URI+"&response_type=code&scope=snsapi_login&state=wxPcLogin#wechat_redirect";

以下为微信回调授权处理代码

public JSONObject weixinAuthLogin(WeixinAuth weixinAuth) throws Exception {
        /**
         * 返回值
         */
        JSONObject returnJson = new JSONObject();

        /**
         * 1.获取access_token
         */
        JSONObject tokenResp = getAccessToken(weixinAuth);
        String accessToken = tokenResp.getString("access_token");
        String openId = tokenResp.getString("openid");

        /**
         * 2.校验token是否有效
         */
        //接口请求参数
        Map authParam = new HashMap<>();
        authParam.put("access_token", accessToken);
        authParam.put("openid", openId);
        //发送请求，获取返回值，校验access_token
        refreshAccessToken(authParam);
        
        /**
         * 3.校验通过，获取用户信息
         */
        //用户信息的参数与校验参数相同
        JSONObject userInfoResponse = getUserInfo(authParam);

        returnJson.putAll(userInfoResponse);
        returnJson.put("whetherLogin", false);
        return returnJson;
    }

/**
     * 获取access_token，并校验返回值
     * @param weixinAuth
     * @return
     * @throws Exception
     */
    private JSONObject getAccessToken(WeixinAuth weixinAuth) throws Exception {
        Map accessTokenParam = new HashMap<>();
        accessTokenParam.put("appid", 你的wxAppId);
        accessTokenParam.put("secret", 你的wxAppSecret);
        accessTokenParam.put("code", weixinAuth.getCode());
        accessTokenParam.put("grant_type", "authorization_code");
        String param = MapUtils.getParamByMap(accessTokenParam);
        //发送请求，获取返回结果
        String tokenResponseStr =
                HttpRequestUtil.sendGet("https://api.weixin.qq.com/sns/oauth2/access_token", param);
        if (StringUtils.isBlank(tokenResponseStr) || !tokenResponseStr.startsWith("{")) {
            logger.error("-------请求微信access_token接口错误：-------" + tokenResponseStr);
            throw new Exception("请求微信access_token接口错误");
        }
        //取出access_token 与 openId
        JSONObject tokenResp = JSONObject.parseObject(tokenResponseStr);
        String openId = tokenResp.getString("openid");
        if (StringUtils.isBlank(openId)) {
            logger.error("-------请求微信access_token接口返回值错误：-------" + tokenResponseStr);
            throw new Exception("请求微信access_token接口返回值错误");
        }
        return tokenResp;
    }

    /**
     * 校验token是否有效
     * @param authParam
     * @throws Exception
     */
    private void refreshAccessToken(Map authParam) throws Exception {
        //发送请求，获取返回值
        String authResponseStr =
                HttpRequestUtil.sendGet("https://api.weixin.qq.com/sns/auth", MapUtils.getParamByMap(authParam));
        // 判断返回值是否正确
        if (StringUtils.isBlank(authResponseStr) || !authResponseStr.startsWith("{")) {
            logger.error("-------请求微信auth接口返回值错误：-------" + authResponseStr);
            throw new Exception("请求微信auth接口返回值错误");
        }
        JSONObject authResponse = JSONObject.parseObject(authResponseStr);
        // 判断token是否有效，如果token失效，重新拉取access_token
        if (!StringUtils.equals("ok", authResponse.getString("errmsg"))) {
            // refresh_token接口参数
            Map refreshTokenParam = new HashMap<>();
            refreshTokenParam.put("appid", wxAppId);
            refreshTokenParam.put("grant_type", "refresh_token");
            refreshTokenParam.put("refresh_token", "REFRESH_TOKEN");
            // 回去返回值
            String refreshTokenResponseStr =
                    HttpRequestUtil.sendGet("https://api.weixin.qq.com/sns/oauth2/refresh_token", MapUtils.getParamByMap(refreshTokenParam));
            // 判断返回值的结果是否出错
            if (StringUtils.isBlank(refreshTokenResponseStr) || !refreshTokenResponseStr.startsWith("{")) {
                logger.error("-------请求微信refresh_token接口错误：-------" + refreshTokenResponseStr);
                throw new Exception("请求微信refresh_token接口错误");
            }
            JSONObject refreshTokenResponse = JSONObject.parseObject(refreshTokenResponseStr);
            if (StringUtils.isBlank(refreshTokenResponse.getString("refresh_token"))) {
                logger.error("-------请求微信refresh_token接口返回值错误：-------" + refreshTokenResponseStr);
                throw new Exception("请求微信refresh_token接口返回值错误");
            }
            // 重新设置access_token
            authParam.put("access_token", refreshTokenResponse.getString("refresh_token"));
        }
    }

    /**
     * 校验通过，获取用户信息
     * @param authParam
     * @return
     * @throws Exception
     */
    private JSONObject getUserInfo(Map authParam) throws Exception {
        /**
         * 3.校验通过，获取用户信息
         */
        //用户信息的参数与校验参数相同
        String userInfoResponseStr =
                HttpRequestUtil.sendGet("https://api.weixin.qq.com/sns/userinfo", MapUtils.getParamByMap(authParam));
        //判断返回值是否正确
        if (StringUtils.isBlank(userInfoResponseStr) || !userInfoResponseStr.startsWith("{")) {
            logger.error("-------请求微信userinfo接口错误：-------" + userInfoResponseStr);
            throw new Exception("请求微信userinfo接口错误");
        }
        JSONObject userInfoResponse = JSONObject.parseObject(userInfoResponseStr);
        if (StringUtils.isBlank(userInfoResponse.getString("openid"))) {
            logger.error("-------请求微信userinfo接口返回值错误：-------" + userInfoResponseStr);
            throw new Exception("请求微信userinfo接口返回值错误");
        }
        return userInfoResponse;
    }

以上代码可同时用于pc和微信公众号回调获取用户信息，需要注意的是，PC微信登录的appid与secrect与微信公众号的appid和appSecrect不同

PC微信的授权为(scope=snsapi_login)

https://open.weixin.qq.com/connect/qrconnect?appid="+APPID+"&redirect_uri="+REDIRECT_URI+"&response_type=code&scope=snsapi_login&state=wxPcLogin#wechat_redirect

微信公众号的授权为(scope=snsapi_userinfo)

https://open.weixin.qq.com/connect/qrconnect?appid="+APPID+"&redirect_uri="+REDIRECT_URI+"&response_type=code&scope=snsapi_userinfo&state=wxPcLogin#wechat_redirect